Improvement in apparatus for liquefying nitrous oxide and otrer gases



WILLBUR F.-JO.HNSTON & WILLIAM A. JOHNSTON.

improvement in Apparatus for Liquifying Nit rous Oxide and other Gases.

N0. 120,977. Patented Nov-14,1871.

WITNESSES; INVENTOR: f Y @4444; 2 w @MZW v UNITED WILBUB F. JOHNSTON ANDWILLIAM A. JOHNSTON, OF BROOKLYN, NEW YORK.

IMPROVEMENT IN APPARATUS FOR LIQUEFYING NITRUUS OXIDE AND OTHER GASES.

Specification forming part of Letters Patent No. 120,977, dated November14, 1871.

To all whom it may concern:

Be it known that we, WILBUR F. JOHNSTON and WILLIAM A. JOHNSTON, both ofBrooklyn, in the county of Kings and State of New York, have invented anImproved Process of Compressing and Liquefying Gases, of which thefollowing is a specification:

The object of our invention is to accomplish the liquefaction, or, wherethat is impossible, the uttermost possible compression of gaseous oraeriform matter. This has been done in an experimental way by the use'of air-pumps, and some very large and costly ones have been constructedwith a View to continuous working on a large scale, but they have notbeen successful.

In practical working it has been found that as soon as the air-pumpswere worked at any very high pressure the valves leaked; and further,the mechanical impossibility of bringing the surfaces of the pistonexactly to the end of the cylinder causes amore serious difficulty. Thegas left in the space between the piston and the cylinder-head expandsimmediately as the piston recedes, and so offers serious obstruction tothe gas, which should be admitted as the piston approaches the other endof the cylinder. We obviate this difficulty by making use of someliquid, as water, to receive and transmit all pressure.

To accomplish our purpose we connect any approved hydraulic pump, B, ofone or more cylinders, with a very strong tank, A, provided at somepoint with a means of attaching a strong bottle or receiver, H, in whichto collect the product of the operation. At L is an opening, providedwith a stop-cock, through which to admit the gas we intend to operateupon from its generator or its receiver, neither of which are hererepresented. Between the pump and the tank is a strong stop-cock, D, andanother, I, between the tank and the bottle.

Having first filled the tank with water for the purpose of completelyexpelling the air from it, we admit into the tank through L whateverquantity of gas we propose to liquefy or condense, displacing, ofcourse, a volume of water equal to the volume of the gas introduced. Wethen close the stop-cock L between the gasometer and the tank and openthe stop-cock I between the receiver and the tank. By setting the pumpin motion we new force water into the tank and so drive the gas into ourreceiver. We carry this compression to any point we choose, limited onlyby the strength of the receiver. required varies with the nature of thegas to be operated upon, but is often far greater than the valves of anyair-pump can stand without leaking while employed to do more thanexperiment. Having driven the gas from our large tank into our receiverin either a liquid or very greatly compressed form, we close thestop-cock I and remove the bottle with its contents. Securing a secondreceiver to the same place and introducing another supply of gas, weagain force water into the tank, and so the gas into our receiver, asbefore.

We find that we can in this way reduce one hundred gallons of nitrousoxide gas to theliquid form in about thirty minutes.

We claim- The condensation or liquefaction of gaseous or aeriform matterby pressure transmitted from a pump by means of a liquid to the matterit is desired to condense.

W. F. JOHNSTON. W. A. JOHNSTON.

Witnesses D. D. WHITNEY,

The pressure

